Safety apparatus



July 25, 1933. i o. A. McNAMEE 1,919,445

SAFETY. APPARATUS Filed Sept. 28 1931 lnventoi':

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V I v OWEN A. IVICNAJVIEE, OF VJORCES'IER, IVIASSAGHUSETTS SAFETY APPARATUS M Application filed September 28, '1931. serial lqo. 565,589.

This is an invention for a safety apparaon the rolls 2 without interfering with the tus for motor driven rolls, it being the inothers. An insulated rod arranged tent-ion of the inventor to provide a means over these levers 8 near their counterfor warnin the operator of a set of rolls when he is in a dangerous position, and to stop the roll s immediately upon givin the warnir A characteristic feature'of the invention is the use of a number of electric conduc- 'acent the rolls to be protected and charged with high tension electricity, whereby the operator of the rolls will be warned by a slight shock of his dangerous position, an electric system being arranged tors it 'to stop the motion of the rolls the moment these conductors are grounded. Such an apparatus applied to a pair of rubber warming and mixing rolls is shown by the accompanying drawing. In the operation of these rolls the operator stands on aconcrete floor in front of them and, as a rule, braces himself against their metallic framework; -When in this position he I is well grounded electrically so that if he touches the conductors, by coming in too close proximity to the rolls, he will complete the high tension circuit and will receive a slight shock which will warn him of his dangerous position. The completion of this circuit will immediately stop the rolls, to further insure the prevention of an accident. In the drawing: Figure 1 is a front elevation of one form of this invention. Figure 2 is an end elevation'of Figure 1.

Figure- 3 is an example of an electric circuit which may be used to stop the rolls when driven by an electric motor. Having reference to this drawing, there is shown a pair of rubber warming and mixing rolls'EZ mounted in a metallic frame 3 for rotation by an electric motor athrough, a gear reduction box 5. An overhead support 6, insulatingly carried by a standard 7, extends along these rolls. A number of levers 8 are pivotally carried by the support 6 at spaced intervals and themselves carry depending chains 9 and chain counterweights 10, any one of these chains being capable of raising to pass lumps of rubber weighted ends so that the chains 9 erly maintainedjii; position. It is to be understood that the counterwei htsflO do not quite balance the chains 9 so that the levers 8will'bear against his rod 12.

The circuit charging the chains 9 and stopping the'motor 4 may consist in a 3- pole relay 13 interposed in l ain line 14 which supplies current to the motor 4. A step-downjtransformer '15 is connected to the line 14 and normally energizes a step up transformer 16 through a second 3-pole relayl'ln This step-up transformer maintains a high voltage, low amperage grounded charge in the chains 9, the relay 17 being balanced for operation by a slight increase in current. moment the chains 9 are grounded, the relay l7 thereupon breaking the circuit to the transformer 16 and closing it to the relay switch 13, which opens the power line 14: so that the motor 4 stops. The relay 17 also closes the circuit from the step-down trans-' former 15 to this relay s operating coil through a resistance 18, this resistance preventing the sudden increase in current which would necessarily occur when the resistance of the step-up transformer was removed.

When the operator of the rolls accident-i ally touchesthe chains 9 he receives a slight shock. This simultaneously causes the in crease mentioned in the above para raph so that the relay l7 breaks the circuit to the transformer 16. and 'closes the relay switch 13, this opening'the power line 14 so that the motor 4 stops and prevents injury to the operator.

Such an increase occurs the are prop- This circuit arrangement is'partic-ularly illustrative of only one method of accomnot been shown with the intention of limiting the scope of. this "invention exactly plishing the desired results and need not 2. A safety device for motor driven rollscomprising an overhead support extending along the rolls to be protected, levers pivotally carried by said support, electric conductors depending from said levers to points adjacent said rolls, counterbalances on said levers for balancing said conductors, means for charging said conductors with high tension electricity'and means operable by the grounding of said conductors for stopping said rolls.

3. A safet device for motor driven rolls,

comprising an overhead support extending along the rolls to be protected, levers pivotally carried by said support, flexible electric conductors depending from said levers to points adjacent said rolls, weights aflixed to the ends of said conductors for maintaining them taut, counterbalances on said levers for balancing said weighted conductors, means for charging said conductors with high tension electricity, said charging means delivering an electrical shock to a person in contact therewith and simultaneously stopping said motor driven rolls.

4. A safety device for motor driven rolls comprising an overhead support extending along the rolls to be protected, levers pivotally carried by said support, flexible electric conductors depending from said levers to points adjacent said rolls, weights aflixed to the ends of said conductors for maintaining them taut, counterbalances on said levers for balancing said weighted conductors, means for charging said conductors with grounded high tension electricity, said charging means delivering an electrical shock to a person in contact therewith and means operable by the grounding of said conductors for stopping said rolls,

OWVEN A. MONAMEE. 

